1. Field of the Invention
The present invention relates to a woodwind instrument and an airflow adjuster, and more particularly, to a woodwind instrument and an airflow adjuster which can reduce undesired sound generated from a tone hole.
2. Description of Related Art
Woodwind instruments such as a clarinet described in Japanese Unexamined Patent Application, First Publication No. H01-158491 have been widely used. In a clarinet, a bell is coupled to a lower tube of a main tube formed from an upper tube and a lower tube. Tone holes are formed in the main tube at predetermined intervals along the axis line direction thereof. By closing and opening these tone holes, the effective length of the tube is changed to perform specific tones. Each tone hole is opened and closed through the use of a key with a pad or the like by manipulating the key with a finger tip. Here, a clarinet having an interval-correcting tone hole formed in a bell part thereof so as to correct the interval of a low-pitched tone (LowE) is known.
However, in the clarinet in which the interval is corrected as described above, since a tone hole is formed in the bell part independently of the tone holes formed in the main tube, there is a problem in that the number of components increases and the adjustment of the keys located in the lower tube and the bell part is complicated. Since the number of components increases, there is a problem in that the work load for adjusting the clearances between the components increases and the manufacturing cost thereof also increases. In addition, when a user combines the bell part with the lower tube, there is a problem in that the keys located therein may collide and bend or the like and thus the keys may be damaged. Therefore, it can be thought that in order to solve the above-mentioned problems, the interval-correcting tone hole could be formed in the lower tube. In this case, there is a problem in that in order to achieve the equivalent interval correction effect, the tone hole should be formed with a hole diameter smaller than that of the tone hole formed in the bell part and this creates undesired sound as wind noise (sound such as hissing noise) from the tone hole during performance. Here, Related Arts 1 to 3 described below can be considered as techniques for suppressing the generation of undesired sound while forming an interval-correcting tone hole in the lower tube.
[Related Art 1]
The hole diameter of the interval-correcting tone hole is set to be greater than the hole diameter of the other tone holes used for the musical performance.
[Related Art 2]
The gap between the interval-correcting tone hole and the key with a pad at an open position at which the tone hole is opened and closed, that is, the pad opening at the interval-correcting tone hole, is set to be as large as possible.
[Related Art 3]
The axis line direction of the interval-correcting tone hole is oblique about the diameter direction of the lower tube and air flowing out of the tone hole is made not to come in contact with the open key with a pad.
However, in Related Art 1, when the hole diameter of the interval-correcting tone hole is increased so as to further reduce undesired sound, the distance of an arm connecting the pad plate to a key tube decreases by the amount by which a pad plate is enlarged. Accordingly, there is a problem in that the stroke of a key with a pad is insufficient, thereby making the performance difficult. Here, it is possible to enlarge the pad opening to satisfactorily guarantee the stroke. However, in this case, the fingering distance increases, and if an effort to reduce the fingering distance by changing the leverage ratio is made, performance is made more difficult by a spring being heavier or the like. In Related Art 2, since the pad opening is enlarged, performance is also difficult as described above.
In Related Art 3, since the tone holes other than the interval-correcting tone hole are formed by drilling the main tube in the diameter direction thereof, it is necessary to separately prepare a machine solely for machining the interval-correcting tone hole. That is, a machining shaft for the interval-correcting tone hole should be added, whereby a facility load of a high-function machine tool corresponding thereto increases.